Support nullable types in mojom.

mojo/public/tools/bindings/pylib/mojom/parse/lexer.py

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import imp
 import os.path
 import sys
 
 # Disable lint check for finding modules:
 # pylint: disable=F0401
@@ skipping 74 matching lines @@
     'INT_CONST_DEC', 'INT_CONST_HEX',
     'FLOAT_CONST',
 
     # String literals
     'STRING_LITERAL',
 
     # Operators
     'MINUS',
     'PLUS',
     'AMP',
+    'QSTN',
 
     # Assignment
     'EQUALS',
 
     # Request / response
     'RESPONSE',
 
     # Delimiters
     'LPAREN', 'RPAREN',         # ( )
     'LBRACKET', 'RBRACKET',     # [ ]
@@ skipping 60 matching lines @@
 
   # Newlines
   def t_NEWLINE(self, t):
     r'\n+'
     t.lexer.lineno += len(t.value)
 
   # Operators
   t_MINUS             = r'-'
   t_PLUS              = r'\+'
   t_AMP               = r'&'
+  t_QSTN              = r'\?'
 
   # =
   t_EQUALS            = r'='
 
   # =>
   t_RESPONSE          = r'=>'
 
   # Delimiters
   t_LPAREN            = r'\('
   t_RPAREN            = r'\)'
@@ skipping 59 matching lines @@
     return t
 
   # Ignore C and C++ style comments
   def t_COMMENT(self, t):
     r'(/\*(.|\n)*?\*/)|(//.*(\n[ \t]*//.*)*)'
     t.lexer.lineno += t.value.count("\n")
 
   def t_error(self, t):
     msg = "Illegal character %s" % repr(t.value[0])
     self._error(msg, t)